>> matt, also ahead we'll air part one of our exclusive interview with president obama. we sat down with him just hours before the attack in boston and asked him whether he thinks congress will pass this new gun legislation, it is hanging by a thread according to some accounts and how worried is he about the provocative rhetoric and actions we've seen from north korean leader kim jong-un. does he think he's stable? we'll hear from him in our exclusive interview coming up. >>> new details on this deadly attack at the boston marathon, lester holt joins me once again here in boston. good morning. >> good morning again. this investigation is moving on so many different levels looking at surveillance videos along the routes, cameras that might have captured something. there were some important developments overnight we want to catch you up on. search warrants were apparently issued in revere, massachusetts. they searched an apartment, they questioned two men, they're not being described as suspects. it's the first of many leads or possible leads that police will be following